A known type of fuel and oil filter includes a shell, a nutplate secured to the shell, and a filter element disposed within the shell. The nutplate includes a threaded aperture through which filtered fluid exits the filter, and which engages with threads on an engine spud to secure the filter to the engine. Filtered fluid that exits the filter through the aperture flows into the engine spud and to the engine. This type of filter is sometimes referred to as a spin-on filter.
In a spin-on filter, an inner elastomeric sealing member is typically provided between the nutplate and a top endplate of the filter element to prevent bypass of fluid around the filter from the unfiltered fluid side to the filtered fluid side. A coil spring is also typically provided between the base of the shell and the bottom of the filter element to bias the filter element upwardly into engagement with the nutplate and enhance the seal between the nutplate and the filter element. However, if the inner sealing member is not installed correctly or the spring does not seat properly against the filter element, an internal bypass situation can result whereby unfiltered fluid can bypass the filter. If this occurs, unfiltered fluid can flow to the engine which can lead to increased engine wear and damage.